SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eba1dbd697fa56f549996819dbb246b238613e7375cc1ab6ac1629e31410ac1f' 
  AND token = 'CgBvZC/QZr9/yz4MXbjQfYZ+T8r0AKOcJvP/VEAHB1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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