SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b371b1b4ec302cd37a5f40bdba2248f53a0b1164a577cc1d9ffa15202e5b12' 
  AND token = 'bLTkOaUUj7yisp5POnoo5DEI/nNWEEc9ExuyGuRp3EI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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