SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e8e40f36d537311ade0ca1a5bf4611f7ea898ea1118cb9f922273d47f9d0efe' 
  AND token = 'jVFA0NBF2RAQsumWwtwtbNLydEDMfF+kbMfffuC/C2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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