SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cfbab7de999afd9054099ee870015f6fcd9620e66355455e0717f3b7e75ce84' 
  AND token = 'Hg4l6ZCWlHIk/el4JVg9VbYMYcPA4CLHNgfo30m5mRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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