SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb9e6fcf98472f0dd06e5d5eb81e568fef0c56415b5a0fdd12c9d99de370daba' 
  AND token = 'GmlQVjOqpBJ8/oQT/idLY45hbKWjESyL+iuT3HTqUYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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