SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28c7994631dcce122b75e14c7f24126693636fc8c5fe59ddd8c3b9e3fee768ce' 
  AND token = 'moq5Dbw2+1bOQ02zMlc7m7wWG2FZYbNY0nhRnq6R/8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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