SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cb39f6c8948a901d07c41c53fbfe33dfafa0747dd5c98cca355c62ee599eee6' 
  AND token = 'KESmFG6CSYNmxwuGzqrg2je+R1Ko1J8g5hpwAzjobxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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