SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '175b7b80036d2cf921ac8c91cdac33336dfef453b3769a90c2d54d8b7bfbaf76' 
  AND token = 'f9ZvDtrufqcBK73uBmgyM2QVAazDjm9htH5hU3Y0LYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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