SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bf91579bdb4252e3a3fa04a735acf17b5e9df7b9ad11da650cd4bba81317e24' 
  AND token = 'UKwPXcA20qAolTOHO2N4VJlQOywDhrrlhNeeVELB8wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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