SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cbd3b901f6663edaa70007acb3f0ade5a4b92caf716876884b71c4c710e0d22' 
  AND token = 'NLnCXVF867qkzqqxkgQrN4UyKq9fEi1KJnZesbb1jwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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