SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '668ef83842ab64483e5654e29b9afa09ccbeb85fa93fa2315475271f06b151df' 
  AND token = 'mgRtnGG40o7RKgoJyHMOfuaF1H8fLJzC7fp1okNOfTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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