SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e13fa58d27c4ed1141d5d0e86214b059692e470e897c13936dacf87fad11849' 
  AND token = '8zJ5BpKPYXtU2fT4mk60wAY+fNynzhKM/I0bKFZag6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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