SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6654b666ec3e601c14fbd5b4bd54d8bba818a078598c9482feb2f13ee35b5f0f' 
  AND token = 'd4RAA+l1YYFS5E3HEHmbZSsiZoIRdqDuCYSnEsDps0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}