SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cb52494deffd35f57d9854b7b1257fe92c78cf31ca1cc55742bf459bcd40493' 
  AND token = 'jjM0WpsIMrhg8z0mst3WpfZlCxXiCTsYtJlkwG9aAjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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