SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0108f12e233d4a57e2d21589ebb8dddad3e806adfb3d11d06f1cb473b3445206' 
  AND token = 'KczMZEwTXqRBXvVAuAFvmKH8Fxt96h+Ye3BTdHwCf44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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