SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52a9dbc875dd8f05e43bcd7b4a56ea11a1782a7718c0b7481268f7fee834a55a' 
  AND token = '95LOnH6D5Khg/unCL/wwUuGuQJYl7bu/dQ0UPxthVq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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