SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4301d379c6ef59eb6d07db1255253a667ff2a6cd720fe3bc563629e17881a8c' 
  AND token = 'oJvq3TENyfjwllEzq7yfXtVzYF6rXQet8NXAvSiOoS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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