SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd86a29eb971751b07c3776a25afd09c577c4f9ed9aa128fc8e891401bfb25024' 
  AND token = 'g5/DoqhfCKz+4RMICt2EJhQnsCySUkWya32DOY6vYQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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