SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fead7b8cf9c8767de4a967116ea47ab1e8c09669b482988bbc7251b2f0d38851' 
  AND token = 'Gb0cTTDbNh27MY3rYr0JFtmcL54eW9ca1SrU3sjCeGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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