SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '657dde31f235ba604c7017c36910094946243d40a11a36cb0de6dbc810c332fb' 
  AND token = 'hOrv5g0+xWJlUj5tfIOEHpNsua3SewUswkBPrPPQD1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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