SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ff7e154112fab394c3ceaaea027b03bc5c2f63d4e1b2dbe45e33686e281fda' 
  AND token = 'HSPyEpnO/YReLdf892EYF4JI9hX/JOX9Em4x7jVychc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}