SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a455414b698b3821fae4d42a73af1a77a93b7b28968cf86227cb7d5e3586c0aa' 
  AND token = 'kOW23dObohSSIuOt4gFtkT5TttQEloqvT4K04ndiZ6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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