SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '605dd1a84cef3858a8eddbcf3acd9e0c54f7d9b4325c866cc7ec1608765c76dc' 
  AND token = '7o4ofxxNbWwzKjKStg96/bR7+fFLdZu0yAdDFh7VC04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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