SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cea8ac0d868357dd3f7ec152d11234729a051ae5d7340c8321bf6a7ee8dde16' 
  AND token = 'obTFJSF461WnePTgw8sMwjo518jpEcUeadDG1hnpiag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}