SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3745d1a2fa517e89f0c5c9ce2a6aa8c62d85b27a32b2c16900399ef891fd6e14' 
  AND token = 'K0ZfqqmPy8+gHOmBGvHgPzJuRW0Kd5inc5Yo13i4XJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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