SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c726dc16d9459524f4086a4268bf309fc661376a2f3ceddeff43ae654d51516f' 
  AND token = 'reqmSktPoeg04LLQSFgvnmL7KKyx74b94YeoZ0hxwUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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