SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d7d376c30caafcb9a80941f63c615195e2708c447cf42ac3af9204655e94809' 
  AND token = 'Dbevx+lwXoxVU3zTb1xq06hu6You3OXjZyh94B2zf8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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