SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '686f10c7472e68bda572830cee73aa35c14f35bd1ab8945fbdb6db94dee08612' 
  AND token = 'GFIvBNvQ0z85jHc/um2Ly++SsCOa1BfQ4Ljfzmw+aHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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