SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3562b9035ab0bd207cd5b31045d6ffdcbb66cafea0f27625f20fc41bda672d51' 
  AND token = 'Myvs+76D+ZHhBIyCRfWnV2VxaPDFt8JMF9pxJ8qWuOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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