SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49b5c7220a652fde8130c1bf8bdca2c20813a0a380a89399dc44897f1618f32f' 
  AND token = '+ySwVvcM4YLuzhSYOkaAHaXGpTfWiZXW5fne9+UcktE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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