SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f0959726e2173304ccf3c48a8f12ad92f25302e49a3d2e6b90e72b3cfc8f751' 
  AND token = 'Pe7zNvtJASvD+/iBtGwWG1Y/VAB0x8V7LHfAsuNBkio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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