SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '949749a1797025cc1769cfc569c556155cc06be041f726ff99bcfbb3f8c409a1' 
  AND token = 'ElIQKZGPydM0TQOPiNEWJMFJ+CC54LY9M0rN8818PR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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