SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80692a33ded2e2e95897ef855ee0a96372d4754b50f7ec4db5f7ef740b129410' 
  AND token = '2+JnMKzYPLomSAAYTCmnwy1+6DEJMYmcFvFRWVFuVIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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