SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445c42070fa8427d966c1c5198e376fa695bb2497361f80751a04df41b32b6f3' 
  AND token = 'UMps+WK5L8NoGM0mjr7SradtgWxoRQLl5+PXpzVXLzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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