SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff60bdc2fd93158cdc797c89fbfb1f49120b932a81183f065e0e33b6cbc77097' 
  AND token = 'wLcjUoVLkZw10rst1AxVkwKdUI9Eq+DsUNf4LbfUp00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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