SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e3870c062a0d573f281a8dd98322203b5bce306d16b8f359ebbc512c5e66582' 
  AND token = 'viLorQvKkEBBqpYJg1DjFQdZEDhI9PYhCYEnlSdYUpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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