SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3ffabeb8612eea22d507cf8f9f4d7bf4f4a29091d07eff6f890eb423dbf9df7' 
  AND token = 'Jg0/tacuyFDKntvz7ECXKDgajJ0klfaNj6i84QSqkP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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