SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5218c04955c793d4ff4dd71c9ed62edbe6a837d628e76ed5ca2f199a1a114f20' 
  AND token = 'bC/vByBmYMOL16SzXZg1vXnAilmh964R2jxHY9SgSTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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