SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5cba24138f707b9898c89d777f213df5f1eac0b1242fbb7d8af68613cabcc94' 
  AND token = 'qgofGhFZ8knEs68qjvmb/A4AwAS7xBmV18cfOi7ZWTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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