SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74584b4839d4d97c41eb6eb4ce9e64af2ed4432150b2c5d58ce8dd7818b3c963' 
  AND token = 'qjfDj3q/Smd9ndQwXrwofNVtkCgQjrqHA3zKx/akz20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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