SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a97a01499ef51affcf7283ddd25784737f886e7c54c1770dd2dc53228b442344' 
  AND token = 'FFfVQQJ2pLEOo9qjmPZ3gnZWhLESAG99ba1IZM/4/m8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}