SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49bf46427dd0b6542b835abe4cfbc8c05198378ee6aac2fc4259d7b2bc41b96d' 
  AND token = '3IFmYLFNd5VJcXeOZjZx076bG+EQq0M/PPK2PUzGRAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}