SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54782d8947d7b3122c2b1fc3d61d05d3e5fe9c359abfc639039a096820758c88' 
  AND token = '5cCTLCOGCFllePjHSHdf2zzcnHLeAr5DaUGGW4wZM7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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