SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f35bd585bea74966b5f7cb9248639f7c09f3af9acb1ae873f4461a15eef7a4f' 
  AND token = 'rcWybaWcHMCQhnxUgWD9RXpZlEvOIAOXJJXAyzq3ndc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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