SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f1621ad8ebb736305ec301166f60d49ebc65a38151099451f460c1350dd2f32' 
  AND token = 'ZAkEOKAGu3a1ko/N5BFOaYlCwHKxjD1cMh4iodaiKFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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