SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aad0273fb8803c1a1e7e5399a40b867e2aadc24005a0fa3016312621f8dd3b9' 
  AND token = 'WTipFCXC94HSyZm+KtXTJMs4PEYUIt7OJPPARlGJqWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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