SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29dc1e99daef791b02802c25f78332c7a5a82948818c1e388d920446d0c67dd2' 
  AND token = 'QQXvqpX5jPd5huOIMl7PBah0EMoxZIHKqFQrJ7/mrgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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