SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07f210fc0b95701bef8c4c5e127ee82e148301457578009c978044d33aaac022' 
  AND token = 'H4GCwprv9nlix8YOZ8/kHxsa8pbRb+sBOe6b1TGzR4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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