SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e60e1c2c70380928a52c329ec341d94a1f3b64d90a6f9b3e95f63f859c2df0c' 
  AND token = 'XeSJWV9ONZCt7ekqctZRAps/pjBpHwWVto2LRaVGtfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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