SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '477b37a23c1926d9b3e1c1ff7cbdb175cccd258ab892c1d5d2c2128e511c89b1' 
  AND token = '2yCEZzZZMOiqtTuKTtBixULO6ziBodc7AQbjyUY48Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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