SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd37625b50ccf2ae8e867eb18631ea712b916239ab07021613472d9a3ec17800' 
  AND token = 'aPync1nUyUWqbaPpLSRSLXAsqkjDSFTRBDSROcOVy+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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