SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2c080cdae77f5da7daa8cac138e46cf90b13fa5fc62e41bbd29c3f1219dbea1' 
  AND token = 'oaOmgdeqrzSfyJg1WH6ot54xpSocduoAYmjMCZhh7EQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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