SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e956a4a73fc0908389118b3a651dbdd5aaf737cf8bc9f81ebbd556a5fb1615c' 
  AND token = 'iNlcK+gP++tpkwKsyZC8zX1VKsW+qwkGsCSzg0CvWls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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