SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a1169652a7675ffd14a8b8156fae7adb32f281e3a2191654adcfdf2e6af685' 
  AND token = '0s7hCPLAIpm9TVa4mNVXmftl3ykcEU9h/UTtg4sbmxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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