SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e372eaf4379926b9705eac559dc09364843ecd5433aa2ff7b96014ecedd9dc4' 
  AND token = 'V/wqZAOucwKFM++zfELockHVXsgJ6AJS1ZkSVCXOAt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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