SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4cb44ac7038e87b176ec0eac966e0130342a417b6aed46a4dcc82dbdbf9d86a' 
  AND token = 'Q2+jA4CjR/SHQYsXZQiZY7XhnuK4sMr4ki8g4KQzEaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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