SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d6256a1378ecf2320ad6a9f7833d63f9e6274ea9607b2f05f79c81e4c3d0269' 
  AND token = '1XdecZsr1ReZUVjGwf03SKTPytlf4FDVOYmWSqmEEyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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