SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa4fcc5a2671d5be5b834714c0ab560e48f91800a06872c8fe6a8f38c72af889' 
  AND token = 'W9d1ePbUND7eE/7y5vEZAJeIQUOa9f0g98DPDyIB7n0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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