SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c5bf075a638a429b8ff507bd18d3290aa46c7353fe52a8ed8a54fb07fd64ef8' 
  AND token = '1y7WKcuGBBE97htzT/K/T1v/rJiIfremopXQwuXXrV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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