SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88066257a2532a3b09812ef346479c9aa55e734a07f12e4b8404662a07870c66' 
  AND token = 'DuO2C/4G7JHIboSF16haTeI2hIJMsZtC94uYcBXKtbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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