SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8897f32b3d22b3dc723e18daf0729d3883c9b3f09f3474aae1f60a03bee8b275' 
  AND token = 'Pp7y9novm/VtGAmcj6DQehzK4VfypF+JBSnYTIcpUkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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