SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f87445bd0965523ee4fd5b6c0a4a3d9f27ea8083d84650a40286e75dd782a44c' 
  AND token = 'ZIOTrfA5pA4HLZAgqHFwgIrmEY/SSmycGb6/LYCei3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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