SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e38b01c8b1f61910a722a9e2cb3f50baf7b247ecddd68b408b51b20aec27495' 
  AND token = 'zX3497Ycun8CoBkwljUfPhb6SJFcUtDRkl8tpT1quEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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