SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbf2761ef8987f04c870bddf3ab04c8915bae733494d59d16111982701a115bb' 
  AND token = 'NPSf6KusaiVaxHr2NvBrLsQsdEt/zw8cBbvNcCES3aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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