SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5405c7ea9b2b7f59eaddcd60b82ea3dde20929f8ecf2bbe62a8a36fe235011a' 
  AND token = '9lRQ/iHCQwA/I4CLwnS8gmClFdMCq6NmeLp3S8Fi79c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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