SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '429e1dfdaa106a23e9f184811b7b94f943de492e46afa3d218e9f358b2419055' 
  AND token = 'a6N7lOyQYYm3SdSffYhI1YxaRupwbxvDcBD7OR2iHXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}