SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c99ba56985753016ada6ece6d1f7cd7a64b4244592ea7731bc8aa71d0eb9e5d' 
  AND token = 'u1YvBGAeuDJ0y7jPtY2I1iqf7xkjaTAj5nO5HwOwEEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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