SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ed562bc0362f8e62b0e76f3c2ce33d33fdfdfdb1089a4363d9dd72e1ce8d2aa' 
  AND token = 'lfRBKOcW3WYJYRg7vU8WJ7jbigZKAbjafpdeu/5wyJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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