SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92a7a1604722f3739801d5d67a9497c262b9594f2984ab0905769ba5cf45473e' 
  AND token = 'FSb/GMXgcm/MfJ//288qzDjsEucIqt8lGZ/EuzX1Y+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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