SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb18c748c15e9bfc4664f9ef0e85878e752c7568fc4379093f27da945f340ec4' 
  AND token = 'XVwHhyWu1OOR9yZFgI5j2IBUeTNtiilb/2q0WZpxChA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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