SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23aec7a5f075b422ed60bb51573fe498f5b1ee7bdc847e6685fbe5167f9b78ef' 
  AND token = 'RgQA2MrbjnERmgeQF+bG94fUniHdiQsZOBNNVKJ5eOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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