SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e1fa8a6b55deb413dbb5cb41d5f32b7b4b702934455bcc6578b56d1b8a4fba' 
  AND token = 'eekth7JpzBO8q4HUaa5hHjUw4UOnpDi3FVRkIVvCO6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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