SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1564761b605aaa613df3fabf94582e867409e8565bfffc37f3e39f4436f8d3b' 
  AND token = '7yMXFv++ZACJTqxIW9jLuKU/9aM94aKyzpBJ4j9tIVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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