SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bc772fc14db4e7a9fa891852f3dafe1d944d1505519a28acf67bac8722a248d' 
  AND token = 'pO1gpIDBCRCtpWVSQVCrwSNRLpqLu+Npqs+bWVKEh/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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