SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1a9345c8ec40e897988ff3ad214182ac8a2b561cba47ce84e705483aeb09f108' 
  AND token = 'pXBAzYSL87mkO43Nr7qgoQAZKTXfjwtDmQDvV+xuo9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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