SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39b65bc1b57eb93bed9c1832d81bef3469c269251d1fcd3d4f10dea453e4cb64' 
  AND token = 'dDgCAGPlfwMuqaZ3iTooTuYc37ArzeigS1BrFa0MACk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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