SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '502df4a8f15a3ee4272f9ac0758ed83108e8e6493777176eb79847fb0bf74f2b' 
  AND token = 'Jy5q+/nX+6zJ0rsMdSIScHCvEXxwsHiQ4yTSWVduka4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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