SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87bc92c827f5385fd302c2200c1c8e08b3199a94eaec953b046ef748f469b79f' 
  AND token = 'LFNcIFnENPHJiXuyFAUcIF1up7CxpeWKOfUwO49AEkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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