SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe1e61975f742b7b575975698b017fd8707ef6a02fb26043bba34a230f55885' 
  AND token = '/0F0HErQCoyWlUXfKesY/r5kXarvFZQwX1POE4pHD5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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