SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2692adac57ed2c3b73bf8be7723779708f890422d81ecc0b1407b356486ae26e' 
  AND token = 'i2Mjsg8QpeUDgsPlVtZysLM1rPEksnCLGbOPhbZ+Tek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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