SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2945968c095b27919c39acbc60586c6410bbed9eb1edc242d4f1542d0f5845ab' 
  AND token = 'm/EBp7wBN3roqcNK1gS6iI8rG+zVEfZm7nMj7voeZzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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