SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a47566036693c5b92e02f4929791afbfbce2d858460ec8a95f2897f2583212' 
  AND token = 'YY5wswsKqPNnj6oKqSnYTJQqBQneKqYahV9ICWpan/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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