SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd29994ade0dc2390628bf74116644fba1d09ee06c63858f380b8e64798356173' 
  AND token = 'UyPPLGFBV6e5TmD89I23AKFq8l13RBXHlr5Lxa4/sKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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