SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0a70c5c821b718747d74a7203749dbf9dd8fd8266ed2a0ae0e882851c08deaa' 
  AND token = 'ygrgLcI7md8Jked+1MQGOjx6ffD8uKiAlaMG70cwLB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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