SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c430426ec493729179bad54ecf86ebdef434b1266b9a8845e6c3a5568a459a8b' 
  AND token = 'hGbXhwVDORcaCzgpfGWir83bwOzdxGZx/U3L3qxVQuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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