SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87658a49f8b0bccf4078c547d2e05ae1770760ec439a4b64ddc761f320434169' 
  AND token = '0v+goJZI87mYBbbg2EwMKIWpmiqeiwED4/qwghZxhrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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