SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79f158357a6a7c7b661ddfbe49c81bf58cf4cb3a5161fb09eb332a6d744e2846' 
  AND token = 'gUw/qMbiCNzirGwi6SsP6md0z+vPvYXJjdjLsLR1vtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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